Friction false twist device

ABSTRACT

A plurality of discs spaced from one another overlap similar spaced discs to form a tortuous path for advancing yarn to be false twisted. The disc rims are formed with yarn contact tracks inclined at an angle of at least 10* to the disc surfaces, the division of the tracks being from 0.05 to 1 times the disc thickness and the disc rims having an arch or vault radius of between 0.5 and 5 times the disc thickness.

UnitedStates Patent [191 Raschle n] 3,820,317 June 28, 1974 FRICTION FALSE-TWIST DEVICE [75] Inventor: Josef Raschle, Buetschwill,

Switzerland [73] Assignee: Heberlien & Co. AG, Gall,

Switzerland [22] Filed: Aug. 30, 1973 [2]] Appl. No.: 392,945

[52] US. Cl. 57/77.4, 57/77.45 [51] Int. Cl. D02g 1/04, DOlh 7/92 [58] Field of Search 57/77.3, 77.45

[56] References Cited UNITED STATES PATENTS 6/1960 Dobson 57/77.4 11/1966 Mclntosh.. 57177.4 12/1972 Sholly 57/77.4

FOREIGN PATENTS OR APPLICATIONS 920,658 3/1963 Great Britain 57/77.4

Primary Examiner-Donald E. Watkins Attorney, Agent, or FirmFitzpatrick, Cella, Harper & Scinto [57] ABSTRACT v and the disc rims having an arch or vault radius of between 0.5 and 5 times the disc thickness.

19 Claims, 5 Drawing Figures 1 FRICTION FALSE-TWIST DEVICE This invention relates to false twist apparatus for texturizing textile yarns, and more particularly, to such apparatus which imparts a twist to the yarn by means of frictional surface contact with the yarn. Apparatus for producing false-twist in textile yarns are known by means of which twist is imparted to the yarn by direct frictional contact of the yarn with rotating surfaces. Thus for example, apparatuses are known in which a number of circular discs are arranged on each of three parallel rotating shafts at certain distances, so that the rims of the discs overlap, the discs being arranged on each rotating shaft so that they penetrate into the spaces provided between the discs placed onthe other rotating shafts.

Furthermore, a false-twist device of this kind is known from British patent specification 1'178397 which comprises a spiral between yarn feeding devices, the spiral acting as a friction element over which the yarn is led while subjected to a pre-tension, the points of contact of the yarn with the spiral moving at the same speed and in the same direction as the yarn itself. The spiral is driven so that the, contact points of the yarn rolling over the same move in the direction of yarn movement so that a force is imparted to the yarn which tends to advance same thus to assist the feeding of the yarn. A disadvantage of the device of this kind consists in that, with the angle of inclination of the spiral necessary to obtain an effective advancing force, the distances existing between the individual oblique tracks are too great, and therefore there are insufficient frictional contact points for the yarn so that safe yarn feeding is not assured.

I have conceived apparatus of the class described by which I am able to eliminate this disadvantage and to provide a friction false-twist device with circular discs arranged on at least two parallel rotatable shafts the rims of which comprise contact tracks placed relatively near one another and extending at an inclination angle of at least with respect to the disc surfaces, like a multi-worm screw. The device of the present invention is characterized in that the division of the tracks i.e. the distance from a point on one track element to a similar point on an adjacent track element measured along a line perpendicular to those elements, corresponds to between 0.05 to 1 times the thickness of the disc, and in that the edges of the discs have a vault or arch radius corresponding to between 0.5 and 5 times the thickness of the disc.

The obliquely extending contact tracks may especially have the shape of raised portions with grooves therebetween. They may however also consist of locations of increased friction which are obtained by appropriate treatment of the edge of the discs. The division of the tracks in vertical section, i.e. perpendicularly with respect to the track, may advantageously be between 0.1 and 0.2 times the disc thickness, and the inclination angle of the tracks may be between and 45, preferably approximately 30.

Therehas thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important,*therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.

Specific embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, forming a part of the specification wherein:

FIG. 1 is a top plan view of the device of my invention;

FIG. 2 is a longitudinal section taken along line A A of FIG. 1;

FIG. 3 is a cross-section taken along line B B of FIG. 2;

FIG. 4 illustrates part of an individual disc in front elevation; and

FIG. 5 is a section taken along line C C of FIG. 4.

According to FIGS. 1 and 2, a carrier 1 fixed in a way not shown on a machine frame is provided with two bores through which are passed two vertical shafts 2, 3, on which, above the carrier 1, there are provided in each case three discs 5, 6, 7; 8, 9, 10, respectively, which are separated by spacers 23, 23, 23". On the shaft 3, there is also pivotally mounted an arm 14 which also has a bore through which is passed a further vertical shaft 4. On the shaft 4 I arrange three discs l1, 12, 13 separated by spacers 24, 24', 24". The arm 14 furthermore has a stop lever 15 (FIG. 1) by means of which the discs 11, l2, 13 can be pivoted between operating and non-operating positions in the latter of which, shown in solid lines in FIG. 1, the yarn can be inserted or removed. The arm 14 can also be fixed in the chosen position. It will be appreciated that the intersection between the discs can also be made adjustable since the arm 14, with shaft 4 and discs 11, 12, 13 can be fixed in various operating positions by means of the stop lever 15. The discs are mutually positioned on the shafts such that the discs of one shaft penetrate into the space provided between the discs of the other shafts.

As shown in FIGS. 2 and 3, rollers l6, l7 and 18 are provided on the shafts 2, 3 and 4, respectively, all below the carrier 1. An endless flat belt 19 is passed around rollers 17 and 18, and an endless flat belt 20 around rollers 16 and 17. The shaft 3 is driven by a motor, not shown. By means of this drive of the shafts 2, 3, 4 the yarn can be inserted or removed in operation. It is essential that also the discs l1, l2, 13 are permanently driven to prevent thread breakages from arising upon insertion of the yarn into operating position. The driving of the three shafts 2, 3 and 4 can also be effected by means of other transmission means such as cog-belts and/or cog-wheels, and it is possible to drive shaft 4 by means of a separate electric motor or to provide an individual electric motor for each shaft 2, 3, 4.

All the discs have vaulted or arched edges which are provided with track elements in the form of lands 21 and grooves 22 extending obliquely with respect to the disc surfaces. FIG. 4 shows the edge of a part of such a disc on an enlarged scale, and FIG. 5 shows a section C C perpendicular with respect to the raised portions and grooves. By way of of example, the inclination angle a of the lands 21 and of the grooves 22 is 30 and the disc thickness 6mm. The division b1 b2 in section C C is 0.2 times the disc thickness, i.e. 1.2 mm. The vault radius R is equal to the discthickness and therefore amounts to 6 mm. The intermediate zones between the vaulted disc edge and the disc surfaces are rounded, the radius r of these rounded portions being 1 mm.

The discs may consist of a material which assures the highest possible wear resistance and at the same time has the highest possible friction coefficient with respect to synthetic yarn material such as polyamides or polyesters and consists for example of metal oxide ceramic material or of a metal body having an oxide coating at least on the rims of the discs. Furthermore, discs of synthetic material having similar characteristics are suitable. The disc bodies and the disc rims may consist of different synthetic materials; polyurethane has proved to be particularly suitable for the rim portion. In a further embodiment, the discs of each shaft can be made exchangeable in a simple manner by unscrewing the threaded screwnuts 25, 26, 27 so that, according to the requirements discs of different thickness, vault, inclination angle, division of the contact tracks and disc material may be used. It is also possible to combine discs consisting of different materials.

The advantages of the apparatus of the present invention consist primarily in that the ratio between tensions of the yarn before entering the twist imparter formed by the discs and after leaving the same is relatively small and in that at the same time an effective advance component is imparted to the yarn in its direction of movement, and in that high twist density is obtained even at yarn delivery speeds of up to 500 m/min.

Theprogressive effects of the object of the invention can be seen from the experimental values shown in the table hereinafter, the experiments having been made with the apparatus described above.

TABLE Experiments l 2 i 3 Fiber material Polyamide 6.6 Polyamide 6.6 Polyester Yarn titer Circumferential speed of the discs in m/min. Yarn delivery speed in m/min Yarn tension before the twist imparter in p Yarn tension after the twist imparter in p Tension ratio Twist density in T/m sured along a line perpendicular. to the track elements corresponds to between 0.05 and 1 times the disc thickness and in that the disc rims are vaulted with a vault radius corresponding to between 0.5 and 5 times the thickness of the disc.

2. Device according to claim 1, characterized in that the division (b 12 of the tracks is between 0.1 and 0.2 times the disc thickness.

3. Device according to claim 1, characterized in that the vault radius (R) of the disc rims corresponds to the thickness of the disc.

4. Device according to claim 1, characterized in that the inclination angle (a) of the contact track elements is between 15 and 45.

5. Device according to claim 1, characterized in that the obliquely extending contact tracks are formed by lands (21) and grooves (22).

6. Device according to claim 1, characterized in that the obliquely extending tracks are formed by portions of high friction coefficient with respect to synthetic yarn relatively to the remainder of the discs.

7. Device according to claim 1, characterized in that the intermediate zones between the vaulted disc rim and the disc surfaces are rounded.

8. Device according to claim 1, characterized in that the discs consist of metal oxide ceramic material.

9. Device according to claim 1, characterized in that the disc consist of a metal body provided with an oxide coating at least on its rims.

10. Device according to claim 1, characterized in that the discs consist of synthetic material.

11. Device according to claim 10, characterized in that the disc bodies and the disc rims consist of different synthetic materials.

12. Device according to claim 1, characterized in that the discs are exchangeable.

13. Device according to claim 1, characterized in that the respective discs consist of different materials.

14. Device according to claim 1, characterized in that the discs are mounted on parallel rotatable shafts, two such shafts (2, 3) being arranged on a fixed carrier (1) and a third shaft (4) on a pivotable arm (14).

15. Device according to claim 14, characterized in that the arm (14) is provided with a stop lever (15) for fixing the arm in different operating positions.

16. Device according to claim 14, cearacterized in that all three shafts (2, 3, 4) are drivable by a common motor by means of transmission means (19, 20).

17. Device according to claim 14, characterized in that at least the shaft (4) arranged on the arm (14) is drivable by a separate motor.

18. Device according to claim 1, characterized in that a plurality of groups of spaced, axially aligned discs overlap one another.

19. Friction false twist device including a plurality of spaced circular discs arranged on each of at least two parallel rotatable shafts the rims of which are formed with yarn contact track elements extending at an inclination of at least 10 with respect to the disc surfaces, characterized in that the track elements are lands and grooves, the division of tracks (b b being between 0.05 and 1 times the disc thickness and in that the disc rims are vaulted with a vault radius corresponding to the thickness of the disc, the inclination angle (a) of the contact track elements being between 15 and 45.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 1 1 7 Dated June 1974 Inventor(s) JOSEF CHLE It is certified that error appears in the'above-identified patent and that said Letters Patent are hereby corrected as shown below:

Front Page, at [73] change "Gall" to Wattwil Front Page, beneath "[21] Appl. No.: 392,945", insert [30] Foreign Application Priority Data Sept. 18, 1972 Switzerland 13641/72 Column 4, line 28, change "disc" to discs line 47,

change "cearacterized" to characterized Signed and sealed this 15th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Arresting Officer Commissioner of Patents FORM PC4050 (10-69) USCOMM-DC 60310-P59 fi U.$. GOVERNIEIY PRINTING OFFICE I"! 03-!$4, 

1. Friction false-twist device including normally overlapping circular discs the rims of which are formed with yarn contact track elements extending at an inclination angle of at least 10* with respect to the disc surfaces, characterized in that the division of the tracks measured along a line perpendicular to the track elements corresponds to between 0.05 and 1 times the disc thickness and in that the disc rims are vaulted with a vault radius corresponding to between 0.5 and 5 times the thickness of the disc.
 2. Device according to claim 1, characterized in that the division (b1 - b2) of the tracks is between 0.1 and 0.2 times the disc thickness.
 3. Device according to claim 1, characterized in that the vault radius (R) of the disc rims corresponds to the thickness of the disc.
 4. Device according to claim 1, characterized in that the inclination angle ( Alpha ) of the contact track elements is between 15* and 45*.
 5. Device according to claim 1, characterized in that the obliquely extending contact tracks are formed by lands (21) and grooves (22).
 6. Device according to claim 1, characterized in that the obliquely extending tracks are formed by poRtions of high friction coefficient with respect to synthetic yarn relatively to the remainder of the discs.
 7. Device according to claim 1, characterized in that the intermediate zones between the vaulted disc rim and the disc surfaces are rounded.
 8. Device according to claim 1, characterized in that the discs consist of metal oxide ceramic material.
 9. Device according to claim 1, characterized in that the disc consist of a metal body provided with an oxide coating at least on its rims.
 10. Device according to claim 1, characterized in that the discs consist of synthetic material.
 11. Device according to claim 10, characterized in that the disc bodies and the disc rims consist of different synthetic materials.
 12. Device according to claim 1, characterized in that the discs are exchangeable.
 13. Device according to claim 1, characterized in that the respective discs consist of different materials.
 14. Device according to claim 1, characterized in that the discs are mounted on parallel rotatable shafts, two such shafts (2, 3) being arranged on a fixed carrier (1) and a third shaft (4) on a pivotable arm (14).
 15. Device according to claim 14, characterized in that the arm (14) is provided with a stop lever (15) for fixing the arm in different operating positions.
 16. Device according to claim 14, cearacterized in that all three shafts (2, 3, 4) are drivable by a common motor by means of transmission means (19, 20).
 17. Device according to claim 14, characterized in that at least the shaft (4) arranged on the arm (14) is drivable by a separate motor.
 18. Device according to claim 1, characterized in that a plurality of groups of spaced, axially aligned discs overlap one another.
 19. Friction false twist device including a plurality of spaced circular discs arranged on each of at least two parallel rotatable shafts the rims of which are formed with yarn contact track elements extending at an inclination of at least 10* with respect to the disc surfaces, characterized in that the track elements are lands and grooves, the division of tracks (b1 - b2) being between 0.05 and 1 times the disc thickness and in that the disc rims are vaulted with a vault radius corresponding to the thickness of the disc, the inclination angle ( Alpha ) of the contact track elements being between 15* and 45*. 